Device for wave length transformation of very short waves



Nov. 2, 1948. K. PosTHuMus 2,453,078

DEVICE FOR WAVE LENGTH TRANSFORMATION OF VERY SHORT WAVES Filed March 1'7, 1943 SOURCE OF SIGNAL r04 2% GE l N V E N TO R K4448 pOST/IUMUJ ATTORN EY Patented Nov. 2, 1948 DEVICE FUR WAVE LENGTH TRAiNSFORM-A TIGN QF-VERY SHORT WAVES Kla'as mi us. Eindhovem fliletheflaiids, assigner t Hartford National Bank and; Trust Company, Hartford, Conn, as trustee ApplicationMarch; 1'7, 1943, Serial No; 479,468- In" the Netherlands-December 5,1940

Section 1', Public Law 690, August 8}, 1946 Patent expires December 1 960 7 Claims. (Cl. 25020.33)

This invention relates to a device for wavelength trans-for-mation, more particularly of very short waves. that the tuning of the input circuit and that of the local generator act upon each other. With the known circuits for the above-stated purpose" it was consequently necessary for the irequency' of the local oscillations toxbe so chosen as to cor, respond approximately aharmonic or a -subharmonic of the signal toi b'e received. I

According to the inventionua. perfect independence of the two tunings is obtained since one diagonal of a bridge connection, of which at least two branches include non-linear" elements which serve for the wavelength transformation, has supplied to it the auxiliary'voltages locally generated, whereas the other diagonal has applied to it the signal voltage.

According to the invention; the'circuit ispreferably so made that. theutwor branches of the bridge connection which coincide. in one of the corner points which hasixtheauxiliary voltage supplied to itare each constituted by adiodeandthe two other branches are: each constitutedllby a capacity.

In one embodiment of the invention the generator for the auxiliary oscillations and the two dirodes are arranged in one envelope, in such manner that the anode of the generator section. is-

coupled capacitatively to an equal degree with the anode of each of the two diodes and thus forms one corner point of the diagonal whichhas Such devices entail the drawback In order that the inventionmaybe better unl derstoodand readily carried into" effect, it will 3 and an anode 4, as well as a double diode having anodes 5 and 6 and a common cathode 2 which constitutes an extension of the cathode of the triode section. Further, a body of conductive material in the form of a coupling plate i is provided which is symmetrically arranged relatively to the two anodes 5 and 6, in such manner that the capacities of the coupling plate and of the anodes 5 and 6 are equal to each other. Further,

. 2 the plate I is connected anode l 'The signal voltage is supplied in push-pull: across the two diode-anodes by means of a; cool-'- pling. transformer 8-, the secondary of which: may be center-tapped directly to ground or" through, a resistance It; in the conventional manner. The" electrode system. consisting of the cathode 2;. the control grid 3- and the anode 4 is connected as a. tri-ode generator for very short waves; for" which; purpose a tunable Lecher wire system; 9 is pro vided between the control grid and the anode. 'Ihe oscillations thus generated are supplied ca. pacitatively and with equal phase to the two diode-anodes 5 and 6- so that frequency-changing occurs inthe two diodes and the desired voltage: of the sum or difference" frequency may be taken from the circuit Ill tuned to this frequency.

Energizing potential. for the" anode 4' of the oscillator section is applied in: the conventional manner from a source of direct current potential;

by a; lead T to the;

represented by +3, through an F; choke I'B'.

Biasing potential for the grid" 3 is? obtained from a sou-roe represented by -G through a grid re;

sistance l'l, a blocking. condenser l8 serving to I isolate the" grid from the source of anode voltage inthe conventional manner.

From theequivalentbridge circuit" of Fig. 2 it is seen that the'oscillatorycircuittuned to the signal frequency and thelLecherwire syst'em tuned tofthe frequency of the auxiliary oscillations" cannot act. upon each other. In thiscircui'tthecapaci-ty be tween the couplingpiate: l and the diode anode 5 is indicated by 01,5 and the capacity between the coupling plate I and the diode anode B by Cm. The two d-iodes are indicated by' Di and Dis respectivelyl As it appears from the diagrams the elements 01,5, Cm, D5 and. Uwconst'itute a bridge connection in which the: corner points I I, I2" of one diagonal have supplied" to theni the- 10 cally generated oscillations of fre uency ft" and the'corner points 1:3; M or the other diagonal iiave supplied:- to them'rthe'rreceived'i oscillations oi l re" quencyfs; I-f' the. bridge connection is balanced; 1

push-pull from the mixing stage, which, especially if the intermediate frequency is comparatively high, is advantageous in view of the next following amplifying stages.

The further advantages of the device according to the invention which can be mentioned are the possibility of greatly reducing the length of the connecting leads between the generator sec- 1 tion and the frequency-changing section, since the electrode systems concerned may be arranged in one envelope, and the possibility of connecting the cathode of the system to earth. Besides, it is in this case very well possible for the generator oscillations "to be generated with a frequency equal, for example, to that of the input signal increased by the intermediate frequency, instead of a harmonic or a subharmonic of this frequency.

What I claim is:

- provided with a pair of diodes and a plurality of additional electrodes, external circuit elements connected to said electrodes constituting an oscillator, said additional electrodes constituting an oscillator section, said diodes and oscillator section having a common cathode, a signal input circuit connected to the diode-anodesQmeans 1. A frequency-changing network adapted to mix a voltage of locally generated oscillations with a signal voltage particularly for use in signalling by means of short waves, comprising a bridge connection constituted by a diode in each of two. branches of the bridge connection and a capacity in each of the two remaining branches, characterized in that the voltage of locally-generated, oscillations is supplied across that diagonal of the bridge across which the dissimilar branches are in series and the signal voltage is applied across the other diagonal across which the similar branches are in series.

2. A frequency-changing network particularly for use in signalling by means of short waves, comprising a bridge connection constituted by a diode in each of two branches of the bridge connection and a capacity in each of the two remaining branches, said diodes having a common cathode which forms one corner point of the bridge, theopposite corner point of said bridge beingformed by the common terminal connection of said capacities, a Voltage source oflocallygenerated oscillations connected across said corner points which constitute one diagonal of the bridge, and a signal voltage source connected across the other diagonal of the bridge.

- 3. In a frequency converter circuit utilizing an.

electron discharge tube provided with a pair of diodes and a plurality of additional electrodes, an input circuit tuned to the signal frequency coupled to the diode-anodes, external circuit elements connected to said additional electrodes constituting an oscillator of a predetermined frequency, coupling means within said discharge tube between the oscillator output and each of the diodes, and a circuit tuned to a frequency resulting from the inter-action between the signal and oscillator frequencies connected between the diode-anodes.

4. In a frequency converter circuit utilizing an electron discharge tube provided with a common cathode, a pair of diode-plates and a plurality of 4 additional electrodes including an anode, an input circuit tuned to the signal frequency coupled to the diode-plates, external circuit elements conwithin said discharge device for coupling the oscillator section to eachof the diode-anodes, and a circuit connected between the diode-anodes for deriving the sum or difference frequency resulting from the inter-action between the signal and oscillator frequencies.

6. A frequency converter system for high frequencies, comprising, in combination, a generator of local oscillations, a pair of diodes, a signal input circuit connected in push-pull to the diodes, a circuit connected between the diode-anodes for deriving the sum or difference frequency resulting from the inter-action between the signal and oscillator frequencies, and the improvement which consists in providing capacitive coupling means from the local oscillator generator to each of the diode-anodes.

7. A frequency converter system as defined in claim 6 wherein the improvement consists in providing the pair of diodes and the electrodes of the oscillation generator in a common envelope, and the output electrode of the generator has connected to it within the envelope a conductive member which is symmetrically arranged with respect to the diode-anodes to provide equal capacitive coupling between the oscillator generator and each of the diodes.

KLAAS POSTI-IUMUS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Netherlands Sept. 16, 1946 

